# Sleep "_Altered State_ of concisouness: sleep, [[dream]], [[hypnosis]] ## Stages Activities captured by EEG changes systematically in sleep. 1. Light sleep. high frequency, low amplitude. Occasional muscle twitches. 2. Breathing and heart rate slow down. 3. Deep sleep. 4. Very deep sleep. Muscle paralysis. Brain produces delta waves (low frequency, high amplitude) 5. Rapid Eye Movement (REM) Dreaming. Muscle paralysis. Intense brain activity (high freq. low amplitude) - As night continues, less time spent in deep sleep, more time in dreaming. 夜长 梦多 ## Benefits - Why do we spend a third of our time sleeping? - Simple motor tasks are not affected by sleep. Sleep quality before the race is not predictive of marathon runners' performance. - **Complex recognition tasks** are significantly affected. - Sleep helps [[memory|learning/memory]]. **Consolidation** process. - Deep sleep consolidates information (declarative memory) - Dreaming consolidates skills (procedural memory) ## Disorders ### Insomnia - Best way to avoid _insomnia_: have a structured life, wake up at the same time, go to bed at the same time. - Insomnia may lead to addiction to sleep medications (Michael Jackson) ### Parasomnia - Muscles are not paralyzed "correctly". - Don't wake people at sleep-walking, put them back to bed instead. ## Time for Sleep [Automated Morningness-Eveningness Questionnaire (AutoMEQ)](https://chronotype-self-test.info/)